Drill-bit.



J. SUHACKI & G. W. COOK.

DRILL BIT. APPLICATION FILED JULY 19, 1911.

Patented May 14, 1912 Witnesses; 6

JOHN SOHACKI. Ann GEORGE w. COOK, or'zanxsvnm, rENNsYLvaum.

DRILL-BIT.

Specification of Letters Pa'tentl Patented May 1a, 1912.

, Application filed July 19, 1911. Serial No. 639,404.

To all whom it may concern:

Be it known that we, JOHN SOHACKI and GEORGE W. CooK, citizens of the United States, residing at Larksville, in the county of Luzerne, State of Pennsylvania, have invented a new and useful Drill-Bit, of which the following is a specification.

v This invention relates to drill bits and particularly to drill bits used in coal Ininin' The object of this invention is to provi e an improved device of this character which will be efiicient'in use, cheap to manufacture and simple in construction.

A further object is to provide ,novel means for adjusting the prongs of the bitas they become worn.

With the above and other objects in view this invention is embodied in a'novel construction, arrangement and combination of parts as hereinafter described and shown in the accompanying drawings in which similar. reference characters indicate similar parts. and in which Figure 1 is a perspective view of the drill bit. Fig. 2 is a face view thereof. Fi 3 is a sectional View on the line 3"3.of ig. 2' Fig. 4 is'a side elevation.

Referring specifically to. the drawings, 5 designates the body of the bit, which is integral, and 6 the shank thereof by which it is secured to the drilling machine or any other mechanism. This body 5 isprovided with a pair of parallel and contiguous dovetailed channels 11 in each face thereof which channels diverge upwardly in one direction when looking toward the faces-thereof and converge upwardly in another directlon or when looking at the side thereof. These.

channelsextend to the'u'pperor outer end of the body and are closed at their lower ends, that is, they do not project to the lower end of the body, and 1n their upper ends are inserted the prongs 9 iyvhich are dove-tail shaped in cross section to fit snugly within the channels.

The upper edges 10 or the noses of the prongs are arranged in an a proximate common vertical plane when 100 ingin the direction of the side of the body, and the pairs of prongs are oppositely arranged at each side of the center of thebody to form a proper drilling action as the body 1s revolved. The body has a series of cross slots 12 1n and extending through the port pns sepa-' rating the ehannels and a bar lp fits in a cross slotof each series to have its ends rojeet into the respective channels thus orming seats for the prongs. A plate 7 for the front and rearface of the body serves as a means to cover the notches therein to retain the bars in position and also serves as a closure for thechannels. These plates are removably secured to the body 5 by means of screws 8.

As the 'drill bit is used the prongs hecome rapidl worn and by removing the plates 7 the ars 13 can be set up one notch after the prongs have been slid outwardly slightly to raise the seats for thesaid prongs. In this manner the prongs can be extended from time to time and new prongs can be substituted from time to time as the old prongs give out as will be apparent. The,, plates 7 being removably secured to the body form convenient means for holding the bars 13 in' position and to also conveniently adjustthe prongs whenever it is desired.

The plates 7 which are arranged over the respective channels and cross slots in being drawn inwardly b the screws 8 clamp the pron s 10 and t e bars 13 in position, there y preventing .ing out of the body.

This device is eiiective in its use and it will bd been attained in an efliclent manner.

Having described the invention what is claimed as new is j I. A drill bit comprising an integral body having a pair of parallel and contiguous the prongs from work seen that the objects aimed at have I channels in one face and extending to one end thereof and having a series of cross slots in and extending through the portion separating the channels, prongs slidable in the channels and projecting therefromya member fitting in one of the, said cross slots to have its ends projecting into the channels'toform seats for the prongs, and means on thesaid face of the body to clamp the prongs and retain the said member in position. I

2.1A.drill bit, comprising 'a-body having a'pair of parallel and conti ous channels in opposite faces and extending to one end thereof, which channels converge toward their upper ends in one direction and diverge toward their upper ends in another direction, the said body having a seriesof cross slots in and extending through the portions separatin the channels, prongs slidable in the c annels and promoting therefrom, a bar fitting in a cross slot of as our own, We have hereto afiixecl our sigeach sexiest}? havlles its BIEdS project iglto tge natures in the presence of two witnesses. res ective 0 anne to orm seats 01' t e sai prongs, and acover plateremovably 5 secured on each face of the body to clamp the saiti prongs and retain the said bars in Witnesses: position. a H. H. DKVENPORT,

In testimony that we claim the foregoing Row. J. BLAIR. 

